We could see following memory info in /proc/xxxx/smaps with THP enabled. 7bea458b3000-7fea458b3000 r--p 00000000 00:13 39989 /dev/zero Size: 4294967296 kB Rss: 10612736 kB Pss: 10612736 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 10612736 kB Private_Dirty: 0 kB Referenced: 10612736 kB Anonymous: 0 kB AnonHugePages: 10612736 kB Swap: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB VmFlags: rd mr mw me which is wrong becuase just huge_zero_page/normal_zero_page is used for /dev/zero. Most of the value should be 0. This patch detects huge_zero_page (original implementation just detect normal_zero_page) and avoids to update the wrong value for huge_zero_page. Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> Signed-off-by: Fengwei Yin <yfw.kernel@xxxxxxxxx> --- Hi Andrew, The patch was reviewed as http://lkml.org/lkml/2014/10/9/109. I didn't get further comments. So I suppose it's ok to send the patch to you for merging. Regards Yin, Fengwei fs/proc/task_mmu.c | 6 ++++-- include/linux/huge_mm.h | 2 ++ mm/huge_memory.c | 5 +++++ mm/memory.c | 4 ++++ 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 4e0388c..735b389 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -474,8 +474,11 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr, if (!page) return; - if (PageAnon(page)) + if (PageAnon(page)) { mss->anonymous += ptent_size; + if (PageTransHuge(page)) + mss->anonymous_thp += HPAGE_PMD_SIZE; + } if (page->index != pgoff) mss->nonlinear += ptent_size; @@ -511,7 +514,6 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_PMD_SIZE, walk); spin_unlock(ptl); - mss->anonymous_thp += HPAGE_PMD_SIZE; return 0; } diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index ad9051b..7080aa1 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -34,6 +34,8 @@ extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, int prot_numa); +extern bool is_huge_zero_pfn(unsigned long pfn); + enum transparent_hugepage_flag { TRANSPARENT_HUGEPAGE_FLAG, TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 74c78aa..7e7880c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -183,6 +183,11 @@ static inline bool is_huge_zero_pmd(pmd_t pmd) return is_huge_zero_page(pmd_page(pmd)); } +bool is_huge_zero_pfn(unsigned long pfn) +{ + return is_huge_zero_page(pfn_to_page(pfn)); +} + static struct page *get_huge_zero_page(void) { struct page *zero_page; diff --git a/mm/memory.c b/mm/memory.c index 1cc6bfb..eebb6c5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -41,6 +41,7 @@ #include <linux/kernel_stat.h> #include <linux/mm.h> #include <linux/hugetlb.h> +#include <linux/huge_mm.h> #include <linux/mman.h> #include <linux/swap.h> #include <linux/highmem.h> @@ -787,6 +788,9 @@ check_pfn: return NULL; } + if (is_huge_zero_pfn(pfn)) + return NULL; + /* * NOTE! We still have PageReserved() pages in the page tables. * eg. VDSO mappings can cause them to exist. -- 2.0.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>